Robin Good: YouTube has just released a "face-blurring" tool that can be utilized on any video uploaded to the platform.
"Whether you want to share sensitive protest footage without exposing the faces of the activists involved, or share the winning point in your 8-year-old’s basketball game without broadcasting the children’s faces to the world, our face blurring technology is a first step towards providing visual anonymity for video on YouTube..."
Here's how it works: "Blurring faces on YouTube is simple. Once you’ve chosen the video that you’d like to edit within our Video Enhancements tool, go to Additional Features and click the “Apply” button below Blur All Faces.
Before you publish, you will see a preview of what your video will look like with faces blurred. When you save the changes to your video, a new copy is created with the blurred faces.
You will then be given the option to delete the original video."
Guide on how to use it: http://support.google.com/youtube/bin/static.py?hl=en&guide=1388381&page=guide.cs&answer=2640535